The difference between Boss and Leader

Boss as a noun:

A swelling, lump or protuberance in an animal, person or object.

Boss as a noun (geology):

A lump-like mass of rock, especially one projecting through a stratum of different rock.

Boss as a noun:

A convex protuberance in hammered work, especially the rounded projection in the centre of a shield.

Boss as a noun (mechanics):

A protrusion, frequently a cylinder of material that extends beyond a hole.

Boss as a noun (architecture):

A knob or projection, usually at the intersection of ribs in a vault.

Boss as a noun (archery):

the target block, made of foam but historically made of hay bales, to which a target face is attached.

Boss as a noun:

A wooden vessel for the mortar used in tiling or masonry, hung by a hook from the laths, or from the rounds of a ladder.

Boss as a noun:

A head or reservoir of water.

Boss as a verb (transitive):

To decorate with bosses; to emboss.

Boss as a noun (obsolete):

A hassock or small seat, especially made from a bundle of straw.

Boss as a noun:

A person who oversees and directs the work of others; a supervisor.

Boss as a noun:

A person in charge of a business or company.

Boss as a noun:

A leader, the head of an organized group or team.

Boss as a noun:

The head of a political party in a given region or district.

Boss as a noun (informal, especially, India):

Boss as a noun (video games):

An enemy, often at the end of a level, that is particularly challenging and must be beaten in order to progress.

Boss as a noun (humorous):

Wife.

Boss as a verb (transitive):

To exercise authoritative control over; to tell (someone) what to do, often repeatedly.

Boss as an adjective (slang, American, Canadian, Liverpool):

Of excellent quality, first-rate.

Leader as a noun (music):

any person that leads or directs one who goes first one having authority to direct one who leads a political party or group of elected party members; sometimes used in titles a person or organization that leads in a certain field in terms of excellence, success, etc. a performer who leads a band, choir, or a section of an orchestra the first violin in a symphony orchestra; the concertmaster

Leader as a noun:

an animal that leads the dominant animal in a pack of animals, such as wolves or lions an animal placed in advance of others, especially on a team of horse, oxen, or dogs

Leader as a noun (botany):

someone or something that leads or conducts a fast-growing terminal shoot of a woody plant a pipe for conducting rain water from a roof to a cistern or to the ground the first, or the principal, editorial article in a newspaper; a leading or main editorial article; a lead story a section of line between the main fishing line and the snell of a hook, intended to be more resistant to bites and harder for a fish to detect than the main fishing line a piece of material at the beginning or end of a reel or roll to allow the material to be threaded or fed onto something, as a reel of film onto a projector or a roll of paper onto a rotary printing press a loss leader or a popular product sold at a normal price a type having a dot or short row of dots upon its face a row of dots, periods, or hyphens, used in tables of contents, etc., to lead the eye across a space to the right word or number a net for leading fish into a pound, weir, etc. a branch or small vein, not important in itself, but indicating the proximity of a better one a block of hard wood pierced with suitable holes for leading ropes in their proper places the drive wheel in any kind of machinery the path taken by electrons from a cloud to ground level, determining the shape of a bolt of lightning